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Diffstat (limited to 'tools/lib/bpf/libbpf.c')
-rw-r--r--tools/lib/bpf/libbpf.c197
1 files changed, 167 insertions, 30 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 05c4db355f28..a557718401e4 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -53,6 +53,7 @@
#include "libbpf_internal.h"
#include "hashmap.h"
#include "bpf_gen_internal.h"
+#include "zip.h"
#ifndef BPF_FS_MAGIC
#define BPF_FS_MAGIC 0xcafe4a11
@@ -798,7 +799,6 @@ bpf_object__add_programs(struct bpf_object *obj, Elf_Data *sec_data,
progs = obj->programs;
nr_progs = obj->nr_programs;
nr_syms = symbols->d_size / sizeof(Elf64_Sym);
- sec_off = 0;
for (i = 0; i < nr_syms; i++) {
sym = elf_sym_by_idx(obj, i);
@@ -2615,7 +2615,7 @@ static int bpf_object__init_maps(struct bpf_object *obj,
strict = !OPTS_GET(opts, relaxed_maps, false);
pin_root_path = OPTS_GET(opts, pin_root_path, NULL);
- err = err ?: bpf_object__init_user_btf_maps(obj, strict, pin_root_path);
+ err = bpf_object__init_user_btf_maps(obj, strict, pin_root_path);
err = err ?: bpf_object__init_global_data_maps(obj);
err = err ?: bpf_object__init_kconfig_map(obj);
err = err ?: bpf_object__init_struct_ops_maps(obj);
@@ -9724,6 +9724,7 @@ struct bpf_link *bpf_program__attach_perf_event_opts(const struct bpf_program *p
char errmsg[STRERR_BUFSIZE];
struct bpf_link_perf *link;
int prog_fd, link_fd = -1, err;
+ bool force_ioctl_attach;
if (!OPTS_VALID(opts, bpf_perf_event_opts))
return libbpf_err_ptr(-EINVAL);
@@ -9747,7 +9748,8 @@ struct bpf_link *bpf_program__attach_perf_event_opts(const struct bpf_program *p
link->link.dealloc = &bpf_link_perf_dealloc;
link->perf_event_fd = pfd;
- if (kernel_supports(prog->obj, FEAT_PERF_LINK)) {
+ force_ioctl_attach = OPTS_GET(opts, force_ioctl_attach, false);
+ if (kernel_supports(prog->obj, FEAT_PERF_LINK) && !force_ioctl_attach) {
DECLARE_LIBBPF_OPTS(bpf_link_create_opts, link_opts,
.perf_event.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0));
@@ -10106,6 +10108,7 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
const struct bpf_kprobe_opts *opts)
{
DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts);
+ enum probe_attach_mode attach_mode;
char errmsg[STRERR_BUFSIZE];
char *legacy_probe = NULL;
struct bpf_link *link;
@@ -10116,11 +10119,32 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
if (!OPTS_VALID(opts, bpf_kprobe_opts))
return libbpf_err_ptr(-EINVAL);
+ attach_mode = OPTS_GET(opts, attach_mode, PROBE_ATTACH_MODE_DEFAULT);
retprobe = OPTS_GET(opts, retprobe, false);
offset = OPTS_GET(opts, offset, 0);
pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0);
legacy = determine_kprobe_perf_type() < 0;
+ switch (attach_mode) {
+ case PROBE_ATTACH_MODE_LEGACY:
+ legacy = true;
+ pe_opts.force_ioctl_attach = true;
+ break;
+ case PROBE_ATTACH_MODE_PERF:
+ if (legacy)
+ return libbpf_err_ptr(-ENOTSUP);
+ pe_opts.force_ioctl_attach = true;
+ break;
+ case PROBE_ATTACH_MODE_LINK:
+ if (legacy || !kernel_supports(prog->obj, FEAT_PERF_LINK))
+ return libbpf_err_ptr(-ENOTSUP);
+ break;
+ case PROBE_ATTACH_MODE_DEFAULT:
+ break;
+ default:
+ return libbpf_err_ptr(-EINVAL);
+ }
+
if (!legacy) {
pfd = perf_event_open_probe(false /* uprobe */, retprobe,
func_name, offset,
@@ -10531,32 +10555,19 @@ static Elf_Scn *elf_find_next_scn_by_type(Elf *elf, int sh_type, Elf_Scn *scn)
return NULL;
}
-/* Find offset of function name in object specified by path. "name" matches
- * symbol name or name@@LIB for library functions.
+/* Find offset of function name in the provided ELF object. "binary_path" is
+ * the path to the ELF binary represented by "elf", and only used for error
+ * reporting matters. "name" matches symbol name or name@@LIB for library
+ * functions.
*/
-static long elf_find_func_offset(const char *binary_path, const char *name)
+static long elf_find_func_offset(Elf *elf, const char *binary_path, const char *name)
{
- int fd, i, sh_types[2] = { SHT_DYNSYM, SHT_SYMTAB };
+ int i, sh_types[2] = { SHT_DYNSYM, SHT_SYMTAB };
bool is_shared_lib, is_name_qualified;
- char errmsg[STRERR_BUFSIZE];
long ret = -ENOENT;
size_t name_len;
GElf_Ehdr ehdr;
- Elf *elf;
- fd = open(binary_path, O_RDONLY | O_CLOEXEC);
- if (fd < 0) {
- ret = -errno;
- pr_warn("failed to open %s: %s\n", binary_path,
- libbpf_strerror_r(ret, errmsg, sizeof(errmsg)));
- return ret;
- }
- elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
- if (!elf) {
- pr_warn("elf: could not read elf from %s: %s\n", binary_path, elf_errmsg(-1));
- close(fd);
- return -LIBBPF_ERRNO__FORMAT;
- }
if (!gelf_getehdr(elf, &ehdr)) {
pr_warn("elf: failed to get ehdr from %s: %s\n", binary_path, elf_errmsg(-1));
ret = -LIBBPF_ERRNO__FORMAT;
@@ -10569,7 +10580,7 @@ static long elf_find_func_offset(const char *binary_path, const char *name)
/* Does name specify "@@LIB"? */
is_name_qualified = strstr(name, "@@") != NULL;
- /* Search SHT_DYNSYM, SHT_SYMTAB for symbol. This search order is used because if
+ /* Search SHT_DYNSYM, SHT_SYMTAB for symbol. This search order is used because if
* a binary is stripped, it may only have SHT_DYNSYM, and a fully-statically
* linked binary may not have SHT_DYMSYM, so absence of a section should not be
* reported as a warning/error.
@@ -10682,11 +10693,101 @@ static long elf_find_func_offset(const char *binary_path, const char *name)
}
}
out:
+ return ret;
+}
+
+/* Find offset of function name in ELF object specified by path. "name" matches
+ * symbol name or name@@LIB for library functions.
+ */
+static long elf_find_func_offset_from_file(const char *binary_path, const char *name)
+{
+ char errmsg[STRERR_BUFSIZE];
+ long ret = -ENOENT;
+ Elf *elf;
+ int fd;
+
+ fd = open(binary_path, O_RDONLY | O_CLOEXEC);
+ if (fd < 0) {
+ ret = -errno;
+ pr_warn("failed to open %s: %s\n", binary_path,
+ libbpf_strerror_r(ret, errmsg, sizeof(errmsg)));
+ return ret;
+ }
+ elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
+ if (!elf) {
+ pr_warn("elf: could not read elf from %s: %s\n", binary_path, elf_errmsg(-1));
+ close(fd);
+ return -LIBBPF_ERRNO__FORMAT;
+ }
+
+ ret = elf_find_func_offset(elf, binary_path, name);
elf_end(elf);
close(fd);
return ret;
}
+/* Find offset of function name in archive specified by path. Currently
+ * supported are .zip files that do not compress their contents, as used on
+ * Android in the form of APKs, for example. "file_name" is the name of the ELF
+ * file inside the archive. "func_name" matches symbol name or name@@LIB for
+ * library functions.
+ *
+ * An overview of the APK format specifically provided here:
+ * https://en.wikipedia.org/w/index.php?title=Apk_(file_format)&oldid=1139099120#Package_contents
+ */
+static long elf_find_func_offset_from_archive(const char *archive_path, const char *file_name,
+ const char *func_name)
+{
+ struct zip_archive *archive;
+ struct zip_entry entry;
+ long ret;
+ Elf *elf;
+
+ archive = zip_archive_open(archive_path);
+ if (IS_ERR(archive)) {
+ ret = PTR_ERR(archive);
+ pr_warn("zip: failed to open %s: %ld\n", archive_path, ret);
+ return ret;
+ }
+
+ ret = zip_archive_find_entry(archive, file_name, &entry);
+ if (ret) {
+ pr_warn("zip: could not find archive member %s in %s: %ld\n", file_name,
+ archive_path, ret);
+ goto out;
+ }
+ pr_debug("zip: found entry for %s in %s at 0x%lx\n", file_name, archive_path,
+ (unsigned long)entry.data_offset);
+
+ if (entry.compression) {
+ pr_warn("zip: entry %s of %s is compressed and cannot be handled\n", file_name,
+ archive_path);
+ ret = -LIBBPF_ERRNO__FORMAT;
+ goto out;
+ }
+
+ elf = elf_memory((void *)entry.data, entry.data_length);
+ if (!elf) {
+ pr_warn("elf: could not read elf file %s from %s: %s\n", file_name, archive_path,
+ elf_errmsg(-1));
+ ret = -LIBBPF_ERRNO__LIBELF;
+ goto out;
+ }
+
+ ret = elf_find_func_offset(elf, file_name, func_name);
+ if (ret > 0) {
+ pr_debug("elf: symbol address match for %s of %s in %s: 0x%x + 0x%lx = 0x%lx\n",
+ func_name, file_name, archive_path, entry.data_offset, ret,
+ ret + entry.data_offset);
+ ret += entry.data_offset;
+ }
+ elf_end(elf);
+
+out:
+ zip_archive_close(archive);
+ return ret;
+}
+
static const char *arch_specific_lib_paths(void)
{
/*
@@ -10772,9 +10873,11 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
const char *binary_path, size_t func_offset,
const struct bpf_uprobe_opts *opts)
{
- DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts);
+ const char *archive_path = NULL, *archive_sep = NULL;
char errmsg[STRERR_BUFSIZE], *legacy_probe = NULL;
- char full_binary_path[PATH_MAX];
+ DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts);
+ enum probe_attach_mode attach_mode;
+ char full_path[PATH_MAX];
struct bpf_link *link;
size_t ref_ctr_off;
int pfd, err;
@@ -10784,6 +10887,7 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
if (!OPTS_VALID(opts, bpf_uprobe_opts))
return libbpf_err_ptr(-EINVAL);
+ attach_mode = OPTS_GET(opts, attach_mode, PROBE_ATTACH_MODE_DEFAULT);
retprobe = OPTS_GET(opts, retprobe, false);
ref_ctr_off = OPTS_GET(opts, ref_ctr_offset, 0);
pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0);
@@ -10791,27 +10895,60 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
if (!binary_path)
return libbpf_err_ptr(-EINVAL);
- if (!strchr(binary_path, '/')) {
- err = resolve_full_path(binary_path, full_binary_path,
- sizeof(full_binary_path));
+ /* Check if "binary_path" refers to an archive. */
+ archive_sep = strstr(binary_path, "!/");
+ if (archive_sep) {
+ full_path[0] = '\0';
+ libbpf_strlcpy(full_path, binary_path,
+ min(sizeof(full_path), (size_t)(archive_sep - binary_path + 1)));
+ archive_path = full_path;
+ binary_path = archive_sep + 2;
+ } else if (!strchr(binary_path, '/')) {
+ err = resolve_full_path(binary_path, full_path, sizeof(full_path));
if (err) {
pr_warn("prog '%s': failed to resolve full path for '%s': %d\n",
prog->name, binary_path, err);
return libbpf_err_ptr(err);
}
- binary_path = full_binary_path;
+ binary_path = full_path;
}
func_name = OPTS_GET(opts, func_name, NULL);
if (func_name) {
long sym_off;
- sym_off = elf_find_func_offset(binary_path, func_name);
+ if (archive_path) {
+ sym_off = elf_find_func_offset_from_archive(archive_path, binary_path,
+ func_name);
+ binary_path = archive_path;
+ } else {
+ sym_off = elf_find_func_offset_from_file(binary_path, func_name);
+ }
if (sym_off < 0)
return libbpf_err_ptr(sym_off);
func_offset += sym_off;
}
legacy = determine_uprobe_perf_type() < 0;
+ switch (attach_mode) {
+ case PROBE_ATTACH_MODE_LEGACY:
+ legacy = true;
+ pe_opts.force_ioctl_attach = true;
+ break;
+ case PROBE_ATTACH_MODE_PERF:
+ if (legacy)
+ return libbpf_err_ptr(-ENOTSUP);
+ pe_opts.force_ioctl_attach = true;
+ break;
+ case PROBE_ATTACH_MODE_LINK:
+ if (legacy || !kernel_supports(prog->obj, FEAT_PERF_LINK))
+ return libbpf_err_ptr(-ENOTSUP);
+ break;
+ case PROBE_ATTACH_MODE_DEFAULT:
+ break;
+ default:
+ return libbpf_err_ptr(-EINVAL);
+ }
+
if (!legacy) {
pfd = perf_event_open_probe(true /* uprobe */, retprobe, binary_path,
func_offset, pid, ref_ctr_off);
generated by cgit v1.2.3 (git 2.39.0) at 2024-10-04 21:23:56 +0300